Impact of a collaborative pharmacy practice model on the treatment of depression in primary care.

The effects of a collaborative pharmacy practice model, in which clinical pharmacy specialists provided medication maintenance and follow-up patient care services at a clinic, on patients' adherence to treatment and satisfaction and costs were studied. A cohort of 13 primary care providers (PCPs) was designated to refer patients diagnosed with depression to the practice model at a staff-model health maintenance organization (HMO) immediately after the initiation of antidepressant medications. Clinical pharmacy specialists proceeded to coordinate follow-up with the patients for six months through a combination of scheduled office visits and telephone calls. Working closely with psychiatric liaisons, pharmacists were granted limited prescribing privileges to provide medication comanagement. These patients' adherence to treatment and satisfaction and costs to the HMO were compared with a control group of patients being treated for depression by the remaining 17 PCPs at the facility. A total of 91 patients were referred to the intervention group and received care from the pharmacists during the 10-month enrollment phase; 129 patients were included in the control group. There were no significant differences between groups regarding age, sex and chronic disease scores. An intent-to-treat analysis of medication adherence revealed that adherence was significantly higher in the intervention group (medication possession ratio, 0.81 versus 0.66) (p = 0.0005). Medication switch rates were higher among intervention patients as well (24% versus 5%) (p = 0.0001). There was a greater decline in the number of visits to PCPs for patients in the intervention group (39% versus 12%) (p = 0.029). A collaborative practice model in which clinical pharmacy specialists managed the medication therapy of patients with mild to moderate depression increased patients' adherence to treatment and their satisfaction and reduced the patients' subsequent visits to PCPs.